1. Field of the Invention:
The present invention relates to an Internet protocol network alternate routing system for rerouting voice signals that are transmitted from an extension telephone from a signal path connected to an Internet protocol network to a leased line or an office line.
2. Description of the Related Art
In recent years, Internet protocol (herein-below abbreviated as IP) networks, in which data and voice signals are integrated and transmitted, have been used in business networks, and efforts are now being made to reduce the operating costs of these networks. In a conventional system that uses an IP network, networks are connected together via analog interfaces or digital interfaces by means of gateway devices, and these gateway devices are further connected to private branch exchanges (herein-below abbreviated PBX) that are connected to telephones and computer terminals. Telephones and computer terminals are therefore connected to each other by way of IP networks.
In a PBX that is provided within an IP network, voice signals are converted to packets and then transmitted. However, there has been the problem that the real-time reproduction of packet voice signals is prevented by the occurrence of trouble or congestion within the IP network, and the level of service is therefore reduced.
This problem has occurred because voice signals could not be rerouted from a signal path that passes by way of an IP network to a TDM (Time Division Multiplexer) leased line or a public telecommunication network. This type of alternate routing could not be realized in a conventional IP network.